Electromagnetic vibrators



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ELECTROMAGNETIC VIBRATORS Filed Dec. 26, 1962 2 Shee'cs-Sheeil l Eby, 2

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Jan. 26, 1965 Filed Dec. 26, 1962 w. v. sPURLlN ELECTROM'AGNETIC vIBRAToRs 2 Sheets-Sheet 2 INVENTOR WML/AM MSPueu/u United States Patent C) 3,167,670 ELECTROMAGNETIC VIBRATORS William V. Spurlin, Indiana, Pa., assignor, by mesne assignments, to Link-Belt Company, Chicago, Ill., a corporation of Illinois Filed Dec. 26, 1962, Ser. No. 247,119 11 Claims. (Cl. S10- 29) This invention relates generally to electromagnetic irnpact vibrators and more particularly to enclosed electromagnetic impact vibrators. Impact vibrators having metal to metal contacts will disintegrate the engaging members due to crystallization. This invention provides an improved structure with resilient means between the striking parts.

Because of the construction impact vibrators are difcult and impractical to enclose. The reason for this is because of the dual spring system in which the two spring systems are disposed at right angles to each other and each spring set has independent vibratory action.

The impact vibrator comprising this invention has only one spring system and the novel construction thereof provides a more simplified impact vibrator of greater efciency that can be completely enclosed to be dust proof.

Another object is the provision of an impact vibrator wherein the impact member is symmetrically positioned relative to the armature.

Another object is the provision of an impact vibrator having dual impact points of greater breadth than the armature and fully as wide as the springs.

Another object is the provision of an impact vibrator having an improved armature and impact member assembly.

Another object is the provision of an impact vibrator having a weighted vibratory member to increase the impact force.

Another object is the provision of a vibrator having a spring and spacer combination of steel springs and hard aluminum alloy spaces or Fiberglas epoxy springs and phenolic spacers.

Another object is the provision of a vibrator having a fabricated base welded to the electromagnetic core which when pointed and having a removable cover with a gasket provides a watertight, sealed enclosure for this vibratory machine.

Another object is a fabricated vibrator base made of ne parts, the electromagnetic core, two end channel members and two side bracket members welded together as a unit and pointed to form a watertight base with a chamber to receive the operating coil. The spring mounted armature and impact members are secured to the base to complete the vibrator which when covered provides a novel watertight vibrator.

Another object is the provision of a vibrator having a cast base with a hollow chamber.

Another object is the provision of an improved impact vibrator having a high durometer impact anvil of natural or synthetic rubber such as 80 to 90 durometers of plastic such as Fiberglas in the form of a mat or cloth with an epoxy resin.

Other objects and advantages of this invention appear hereinafter in the following description and claims.

The accompanying drawings show for the purpose of exemplication without limiting this invention or the claims thereto, certain practical embodiments illustrating the principles of this invention, wherein FIG. l is a view in side elevation of a vibratory motor with the base and the cover shown in section.

FIG. 2 is a plan view of the vibratory motor shown in FIG. 1 with parts of the cover broken away.

FIG. 3 is an end view of the vibrator shown in FIGS. 1 and 2 with parts in section.

Patented Jan. 26, 1965 FIG. 4 is a plan view of a modified form of vibrator with the cover removed.

l FIG. 5 is a view in side elevation with the motor shown in FIG. 4 with the base and the cover illustrated in section.

FIG. 6 is a view in vertical transverse section of the structure illustrated in FIGS. 4 and 5.

Referring to FIGS. 1 to 3 the vibrator 1 shown comprises a fabricated base 2 made of opposed channel members 3 constructed of an angle member 4 and a single plate 5 having a large central opening welded along the line 6 to each of the angle brackets 4 to form a single unitary member. The reason for this is that the angle member 4 and the plate 5 form a unitary channel member 3 that is not ordinarily a production item as a channel member. The web faces 7 of these channel base members 3 are welded to the ends of the E-shaped magnetic core 8 made up of a series of E-shaped laminations secured and riveted together between the end brackets 10 by the rivet members 11. The end brackets 10 are materially heavier than the end plates 12 of the core member 8. However, they need not be as thick as ythe channel members 3. The length of the bracket members 10 is substantially the same as the length of the core member 8 so that the bracket members 10 and the core member 8 have a flush engagement with the back faces 7 of the channel members 3 and are welded thereto as indicated at 14.

A pair of spaced plate members 15 are welded as indicated at 16 to the top of the flanges of the angle member 4 and to the surface and as indicated at 17 to the outer face of the vertical flange of the angle member 4 and to the under surface of the plates 5 as indicated at 18. These spaced plates 15 provide rigidity in the channel members 3 and are also provided with an opening 20 for handling or otherwise supporting the vibrator. Thus the base 2 of the vibrator 1 includes a fabrication of several metal parts and when painted provides a watertight sealed base with a chamber 21 having an upwardly facing annular seat 22 on which the cover 23 may be mounted with a gasket 24 and bolted in place by the bolt members 25 for completely enclosing and sealing the interior chamber 21.

As shown particularly in FIGS. 1 and 3 an electromagnetic coil 26 is mounted on the center leg of the E-shaped core 8 and this coil has wrapped therein a mounting bolt 27 that extends through the brackets 10 and is provided with a nut and lock washer as indicated at 28 for securing the coil to the base and on the E- shaped core 8. A washer 29 may be placed between the bottom of the coil and the core and bracket members 10 as shown in FIG. 3.

It will be noted that the pole faces 30 of the E-shaped core are flush with the upwardly facing annular surface 22 on the plate 5 and the upper ends of these pole faces extend upwardly within the central opening 31 in the plate 5.

The end sections of the plate 5 suppont the spring fastening assembly 32 which consists of an impact anvil member 33 that rest immediately on the surface 22 on the opposite ends of the plate 5 and which are substantially larger than the spacer block 34 on which is mounted the shim members 35, the spring members 36 and the clamping block 37 which is secured to the base by the bolts 39. Aside from the shim members 35 the spacers 38 are provided between each of the springs 36 and the springs and the members 34 and 37. These spacers are of a specific character of material depending upon the character of material of the springs.

If the anvil member 33 is provided with a striking anvil, this may be arranged to carry the striking anvil 40 which can be made of rubber having a durometer index of from 80 to 90. If a more dense material is needed as the anvil 40 then a material such as Fiberglas combined with an epoxy resin may be employed to form the anvil 40. This anvil is preferably positioned substantially direotly over the vertical flange of the angle members 4 of the base so as to transmit the impact from the anvil member directly through the middle of the base to the object to be vibrated such as indicated at 41 and which would be bolted to the base member by the bolt members 42.

If the spring members 36 are made of steel then the spacer 38 should be constructed of fairly thick hard aluminum washers which would permit the spring members to flex and deform the Washers 38 within the elastic limit of the hard aluminum alloy. This prevents any actual movemernt between the metal steel spring and the steel clamping block 37 but requires all the movement to be taken up by the hard aluminum alloy spacer 38 within the elastic limit of the same and thereby prevent aking of the steel springs adjacent to fthe position where they are clamped.

If these springs 36 are made of Fiberglas with an epoxy resin then the spacers 38 would be selected with a phenolic resin enclosing and combining a Fiberglas cloth structure. The phenolic reinforced with Fiberglas would perform substantially the same function in substantially the same manner as the hard aluminum alloy. However, the Fiberglas epoxy spring has a greater yieldability than the steel springs and thus some movement may be absorbed within the elastic limits of both the Fiberglas epoxy spring and the phenolic Fiberglas spacers.

Depending upon the nature and the material employed as the springs and the spacers in the clamping assemblies 32 the same type of spacers will be employed as indicated at 38 in the center of the structure wherein three bolts 43 are employed to bolt the armature assembly to the center of the springs 36 with the spacer washers 38 intervening. Referring to this armature assembly the armature member 44 which is preferably a structure made of a series of straight laminations rooted together by the rivets 45 and welded as indicated at 46 to the underside of the impact member 47 which extends beyond the ends of the armature and is preferably made of steel and overlies the anvil members 40 so as to engage the same on every electromagnetic impulse created in the core 8 by the coil member 26 so as to transmit to the anvil 40 the vibratory forces as a product of this electromagnetic vibrator.

The bolts 43 are threaded into the impact member 47 and thus clamp the springs to this armature assembly.

If the structure requires a heavy impact forces a weight such as the middle weight member 48 is bolted to Ithe upper side of the spring assembly by the armature bolts 43 and with this weight and the weight of the impact member 47 together with the weighlt of the armature 44 and the spring members 36 provide a vibratory system that will have a natural period of vibration and the springs 36 are selected so as to provide a tuned vibratory system having a natural frequency tuned to be within a few cycles of the frequency of the electric impulses supplied to the coil 26. This might be an alternating current frequency or an impulse current derived from a half wave of a current of an alternating frequency. The alternating current frequency would, therefore, provide twice the electromagnetic impulses as that delivered by a frequency provided through a half wave of an alternating current frequency. In other words, 60 cycles per second would be given with a rectified current from an alternating current of 60 cycles and 120 vibrations per second would be provided if the rectifier was not employed in the 60 cycle circuit. By changing the voltage supplied to the coil 26 one may change the amplitude and thus the impact strength delivered by the impact member 47 to the anvil 40.

Referring to FIGS. 4, and 6, the vibraftor 50 is provided with a base 51 which may be bolted to the device to be vibrated passing bolts through the bolt holes 52. The base 51 is a hollowed casting having a chamber 53 open at the top. The chamber 53 has the E-shaped core 54 secured in the botitom thereof by the bolts 55 and its center leg is provided with electromagnetic coil 56. The base casting 51 is longer than it is wide and its ends are provided with an anvil block pad 57 on which is mounted a bridge block 58 for the purpose of receiving four aluminum spacers 60 on each side of the three steel leaf springs 61. The top clamping block 62 is mounted over the uppermost hard aluminum spacer and the whole assembly is bolted down by the bolts 63 which extend into threaded openings 64 to the base casting 51.

The center of the leaf springs are provided with the same number of spacers 60 which are clamped between the armature member 65 and the transverse weight 66 by the bolts 67 which bolt this assembly to the mid-position of the springs. In this instance the impact member 68 is made of steel and has a central opening to receive [the armature 65, the latter being welded therein and the bolts 67 are secured only to the impact member 68 and the armature is free of the springs and the spacer members 60. Thus the armature 65 and the impact member 68 lie in the same plane. It would be noted from FIGS. 4 and 6 that the springs 61 are not as wide as lthe impact member 68 but are as wide as the armature 65.

In this particular vibrator if the spring thickness is one-thirty-second of an inch thick, the hard aluminum spacers would be one-sixteenth of an inch thick or twice the thickness of the spring. This particular vibrator could, of course, be provided with thicker springs if it was desired to have a structure the natural period of vibration of which would be different than that of the structure shown.

The mounting bolt 27 is bent laterally above the threaded section and is then flattened to fold into the tape lwrapping on the coil 26. The coil may be partially wrapped with the cloth or Fiberglas tape before the coil mounting bolt is inserted in place. The end of the flat section of the bolt 27 is bent over to form a foot or hook that lies on the transverse portion of the coil. After completing the wrapping of this anchor bolt 27 into the coil by the tape it is impregnated by a resin such as an epoxy or a polyvinyl resin which when polymerized or cured forms a sealed in hard shell and the anchor bolt 27 is an integral part thereof. When the anchor bolt 27 is secured by the nut 28 to the base the coil is drawn down tight and not only escapes injury due to vibration but also provides a better heat dissipation to the metal base.

I claim:

l. A vibrator consisting of a base the underside of which is arranged to be secured to the object to be vibrated and having an opening extending upwardly therefrom, a magnetic core with pole faces and secured to said base within said opening to expose said pole faces upwardly, an operating coil mounted on said core, leaf spring means the ends of which are secured to said base to span said opening above said pole faces, an armature secured to the underside of said leaf spring means to match and be supported in operative spaced relation above said pole faces, and a striker secured with said armature to said leaf spring means and extending beyond said armature to engage said base when said coil is energized to attract said armature.

2. The vibrator of claim 1 characterized by a pad of nonmetallic material secured to said base under said striker to be engaged thereby.

3. The vibrator of claim 1 characterized in that said striker extends beyond both ends of said armature to engage said base but is shorter than said leaf spring means.

4. The vibrator of claim 1 characterized by an upwardly facing continuous annular perimetral surface on said base, and cover means extending over said leaf spring means and engaging said continuous annular perimetral surface to completely enclose the same.

5. The Vibrator of claim 1 characterized in that said striker is a stiff solid metal member and said armature is secured to the underside thereof.

6. The vibrator of claim 1 characterized in that said striker is a stiff metal member having an opening therein, and means to secure said armature in said opening.

7. The vibrator of claim 1 characterized in that said base consists of a pair of spaced channel members with their Web faces opposed and extending parallel to each other and their flanges projecting outwardly, a pair of bracket members secured to the opposite sides of said core and having their ends secured to said web faces to enclose the bottom of said base.

8. The vibrator of claim 7 characterized in that the upper surface of said channels land said brackets form an upwardly facing continuous yannular perimetral surface on said base, and cover means extending over said leaf spring means and engaging said continuous annular perimetral surface to completely enclose the same.

9. The vibrator of claim 1 characterized by Weight means secured to said leaf spring means above the same and by the sarne means that secures the armature thereto.

10. The vibrator of claim 1 characterized in that said Weight means is coextensive with said striker.

11. A vibrator having a base with an electromagnetic core mounted thereon and providing pole faces for attracting an armature mounted in operative spaced relation relative to said core pole faces by spring means supported from the base and consisting of a ring shaped coil spirally wound with insulating tape and mounted on said magnetic core, a mounting bolt threaded at one end and having its other end embracing a lateral portion of said coil and interleaved in the wrapped tape of said coil with the threaded end exposed, a polymerized plastic impregnated tape wrapping to seal and unify said coil and the mounting bolt therein, and nut means engaging said threaded section to lock said coil on said core and to said base.

No references cited.

MILTON O. HIRSHFIELD, Primary Examiner. 

1. A VIBRATOR CONSISTING OF A BASE THE UNDERSIDE OF WHICH IS ARRANGED TO BE SECURED TO THE OBJECT TO BE VIBRATED AND HAVING AN OPENING EXTENDING UPWARDLY THEREFROM, A MAGNETIC CORE WITH THE POLE FACES AND SECURED TO SAID BASE WITHIN SAID OPENING TO EXPOSE SAID POLE FACES UPWARDLY, AN OPERATING COIL MOUNTED ON SAID CORE, LEAF SPRING MEANS THE ENDS OF WHICH ARE SECURED TO SAID BAST TO SPAN SAID OPENING ABOVE SAID POLE FACES, AN ARMATURE SECURED TO THE UNDERSIDE OF SAID LEAF SPRING MEANS TO MATCH AND BE SUPPORTED IN OPERATIVE SPACED RELATION ABOVE SAID POLE FACES, AND A STRIKER SECURED WITH SAID ARMATURE TO SAID LEAF SPRING MEANS AND EXTENDING BEYOND SAID ARMATURE TO ENGAGE SAID BASE WHEN SAID COIL IS ENERGIZED TO ATTRACT SAID ARMATURE. 